I get this error whenever someone joins:

[14:37:10] [Craft Scheduler Thread - 3968/WARN]: Exception in thread "Craft Scheduler Thread - 3968" [14:37:10] [Craft Scheduler Thread - 3968/WARN]: org.apache.commons.lang.UnhandledException: Plugin Essentials v2.0.1-b354 generated an exception while executing task 75140 at org.bukkit.craftbukkit.v1_10_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:56) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NoSuchMethodError: com.earth2me.essentials.ISettings.isSpawnOnJoin()Z at com.earth2me.essentials.spawn.EssentialsSpawnPlayerListener.delayedJoin(EssentialsSpawnPlayerListener.java:75) at com.earth2me.essentials.spawn.EssentialsSpawnPlayerListener$1.run(EssentialsSpawnPlayerListener.java:66) at org.bukkit.craftbukkit.v1_10_R1.scheduler.CraftTask.run(CraftTask.java:71) at org.bukkit.craftbukkit.v1_10_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:53) ... 3 more

Please update EssentialsX. If you ever update other EssentialsX plugins you must always ensure EssentialsX is up to date.